1. Field of the Invention
The present invention relates to a manufacturing method and a manufacturing device of a motor coil to be used in an automobile and the like, and particularly relates to a technique for efficiently peeling a film on a tip portion of a flat conductor.
2. Description of Related Art
In recent years, automobiles that use a motor as a drive source, such as hybrid vehicles and electric vehicles, have been developed. In order to use the motor as the drive source of the automobiles, high efficiency and downsizing of the motor have been desired. Such a demand for downsizing of the motor is especially high for the hybrid vehicles because an engine, the motor, and motor auxiliaries have to be installed in an engine room. Meanwhile, further efficiency of the motor has been desired to improve fuel economy of automobiles. In order to accomplish these objectives, it has been considered to adopt a flat conductor as a coil to be used in the motor. Although the flat conductor is coated with an insulating film, in order to form the coil into a circuit, the film has to be peeled partially to join the coils to one another.
Japanese Patent Application Publication No. 05-111731 (JP 05-111731 A) discloses a technique that pertains to a device for peeling and cutting a film of a flat wire. After the plural flat wires are unwound from plural material bobbins and layered, they are conveyed together to a peeling means. Then, surfaces of the flat wires are peeled by a first peeling machine each time the flat wires of a specified length pass. Next, the layered wires are separated by a separator for parallel alignment, and coatings in a parallel direction are further peeled by a second peeling machine per specified length. The wires having peeled portions as end portions are continuously cut into a specified length by a cutting mechanism.
Japanese Patent Application Publication No. 2011-250597 (JP 2011-250597 A) discloses a technique that pertains to a peeling device for a coated electric wire and to a rotating electric machine having a coil that is peeled by this peeling device. This peeling device includes: a cutting blade; a rotating mechanism that rotates the cutting blade in a circumferential direction of the coated electric wire to be cut; a cutting mechanism that cuts into the coating of the coated electric wire with the cutting blade; and a peeling mechanism that peels the coating of the coated electric wire by the cutting blade. The cutting mechanism is provided with a link mechanism that converts a driving force of a motor into a vertical reciprocal motion of the cutting blade with respect to the coated electric wire. The cutting blades are circumferentially arranged at substantially equally spaced intervals on a concentric circle with the coated electric wire.
However, it is considered that the peeling device that adopts the techniques disclosed in JP 05-111731 A and JP 2011-250597 A has following problems.
In JP 05-111731 A, the material is unwound from the bobbin and peeled at a specified position. In addition, the material is continuously conveyed to be worked. Consequently, there is possible accumulation of a conveyance error. In order to prevent damage on the wire, it is considered to clamp an outer surface of the wire for conveyance. However, in this case, because the wire is clamped to prevent the damage on the outer surface and then conveyed, it becomes difficult to accurately convey the wire for a specified distance without producing the error. This leads to a difficulty in increasing the accuracy in a longitudinal position of the wire due to the error in a peeling position of the wire, for example. Meanwhile, in the technique disclosed in JP 2011-250597 A, the blade is rotated while cutting a tip of the wire. Therefore, it is considered that the wire has to be positioned each time it is cut. However, because an operation to convey the wire to a working position is complicated, lead time may be extended. Eventually, this may have an adverse affect on a product price.